body {
  margin: 0;
  padding: 0;
  background: #333;
}

.middle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.bar {
  width: 6px;
  height: 60px;
  background: white;
  display: inline-block;
  transform-origin: bottom center;
  animation: loading 1.5s ease-in-out infinite;
}

.bar1 {
  animation-delay: .1s;
}

.bar2 {
  animation-delay: .2s;
}

.bar3 {
  animation-delay: .3s;
}

.bar4 {
  animation-delay: .4s;
}

.bar5 {
  animation-delay: .5s;
}

.bar6 {
  animation-delay: .6s;
}

.bar7 {
  animation-delay: .7s;
}

.bar8 {
  animation-delay: .8s;
}

@keyframes loading {
  0% {
    transform: scaleY(.1);
    background: #fff;
  }

  50% {
    transform: scaleY(1);
    background: #2ecc71;
  }

  100% {
    transform: scaleY(.1);
    background: transparent;
  }
}